Bag Including Easy Open Feature and Method of Construction

ABSTRACT

A bag for containing food products or the like comprises a tubular body section with flanged end seals, having the structural seam creating the tubular body section of the bag positioned along the edge of the bag and incorporated as a tear propagation feature to promote ease of opening and enhanced product access.

CROSS REFERENCE TO RELATED APPLICATION

The included application claims the benefit of Provisional PatentApplication No. 61/964,242 dated Dec. 30, 2013.

FIELD OF THE INVENTION

The present invention relates to food bags that include an easy-openfeature and enhanced product access, and which are produced usingvertical packaging machinery.

BACKGROUND OF THE INVENTION

Many consumers have difficulty opening plastic food bags due to thestrength of the packaging films that are used to construct the bagsand/or the strength of the seals featured on the top and bottom of thebag. Most users open plastic food bags by grabbing the bag by each side,then bursting the top seal by pulling outwards on the bag material. Insome instances, the bag may be difficult to open due to the strength ofthe seal or the inability of the user to grab the bag material, anaction which can be especially difficult for older adults as well asyoung children. For these individuals, grasping the sides of a plasticbag may be a difficult task due to limited hand strength. In addition,the bag may burst or tear in an irregular manner or, if it cannot beopened by a manual technique, a cutting device such as a scissors may berequired. To address this problem, several techniques have beenintroduced to provide an opening structure for a bag. Most designsemploy a tear feature which incorporates a tear path running parallel tothe top transverse seal. Patents including Vaughn (U.S. Pat. No.8,690,431) and Mobs (U.S. Pat. No. 6,352,364) describe varioustechniques that are employed to overcome the tear resistance created bythe presence of the body seam in the tear path. Other designs include afunction wherein a corner portion of the bag is removed to allow accessto the contents as shown in Patents Eilert (U.S. Pat. No. 7,971,717) andEdwards (U.S. Pat. No. 8,740,458). While these concepts may assist inopening a bag, they typically provide limited convenience for the user.In consideration of these limitations, the present invention describes afood bag which includes an easy-open tear feature that is convenient forthe consumer while also providing enhanced product access.

BRIEF SUMMARY OF THE INVENTION

The invention relates to flexible bags that feature a main body seamthat extends from the top of the bag to the bottom of the bag therebycreating the ‘tube’ form of the bag. The invention describes aconstruction technique for producing a bag of this design wherein thebody seam incorporated into the bag during construction is utilized as atear element to more easily open the bag while also providing enhancedaccess to the contents. The invention can best be described as being aflexible bag which utilizes the body seam that is created in theproduction of the tubular body section as a tear strip to more easilyopen the bag.

Food products including snack foods are often packaged in bags formedfrom flexible packaging films. These films are formed primarily ofplastics such as polypropylene and polyethylene, but can also containmetalized plastic, foil, paper or oriented films. An exemplary film foruse when packaging food products is described as being an orientedpolymer material that is specially treated to allow long polymericmolecules to align in a given direction, thereby causing the material topreferentially tear in that direction.

Bag construction is accomplished by supplying bag material from a feedroll through a bag making machine wherein the material is wrapped arounda forming tube and sealed to itself, thereby producing the tubular bodysection of the bag. This type of bag construction is typicallyaccomplished on what are known in the industry as verticalform-fill-seal machines. Construction of a bag utilizing these types ofmachines involves positioning the bag material around a funnel shapedforming tube into which product to be included in the bag is inserted.The bag material is pulled around the outside of the forming tube andone end of the bag material is sealed to the other end of the material,typically through use of a heated sealing bar or other sealing deviceincluding ultrasonic, laser seals, cold seal adhesive or otherappropriate sealing means. After the body seam is produced, the tubularbody section of the bag is sealed at the bottom through a transverseflange seal, the desired product is inserted and the filled bag movesdownward off of the forming tube wherein the top transverse flange sealis made. During the action of sealing the top of the first bag, thebottom of the second bag may be simultaneously sealed. The filled andsealed bag is then separated from the bag machine and the sameform-fill-seal production sequence continues with the next bag andsubsequent bags thereafter. This process produces what is referred to inthe industry as a ‘pillow bag’ due to its resemblance to a pillow, andis typically used for packaging snack foods such as potato chips,popcorn or the like.

The vertical body seam typically comprises a double layer seam whereinthe bag material is formed into a tube with the ends of the materialoverlapped onto itself and sealed, an action which produces a flat,non-projecting seam on the body section of the bag. In a secondembodiment, the vertical body seam may comprise a flange style seam thatcould best be described as being a seam produced wherein the inside ofone end of the bag material is sealed to the corresponding inside of theother end of the bag material in a manner similar to the transverse topand bottom flange seals. This type of seam will project from the bodyportion of the bag, or in an additional procedure, the flange could befolded back onto the rear face of the bag and pinned through action ofthe top and bottom transverse seals. In an additional embodiment, atubular body seam may comprise a butt seam wherein the ends of thematerial are bonded together edge to edge therein eliminating anyoverlap of material. As such, this type of seam will reduce the amountof material required to produce the bag and thereby lower constructioncosts.

Any type of body seam that would contribute to the action of the openingstructure herein described could be incorporated without deviating fromthe scope of the invention.

When a conventional food bag is assembled, filled and sealed, the bodyseam for the bag is typically located down the middle of the back sideof the bag. A disadvantage to positioning the body seam in the middle ofthe back side of the bag is that the center position of the seamcompromises the print and graphics that could be included on the backside of the bag. In addition, a consumer will need to open the bag fromone of the two sealed ends, which typically are the shorter sides of thebag and which therein limit access to the contents.

The present invention repositions the vertical body seam from the middleof the back side of the bag to a position in close proximity to the sideedge of the bag, best described as running vertically, or in-line withthe bag construction direction, from the end of the top transverseflange seal to the end of the bottom transverse flange seal. In apreferred embodiment, the seam will be located along the side edge ofthe bag with the overlapped portion or width of the seam located on theback side of the bag to prevent interference with graphics located onthe front side. It should be noted that the seam could also be locatedon the actual edge of the bag with the seam partially or fully visiblefrom the front side of the bag without deviating from the scope of theinvention.

In a preferred embodiment, the top and/or bottom transverse flange sealsof the bag will include a notch or cut located inboard from the edge ofthe bag, a distance from the edge of the bag equal to at least the widthof the body seam. To open the bag, a user will grasp the top of the bagnear the location of the notch and pull the body seam outward anddownward, an action which will initiate a tear in the bag material andwhich will result in the body seam and a portion of the bag materialpulling away and separating from the bag. This same tear promotingaction could be accomplished to a lesser degree through use of acontinuous serrated cut incorporated as the cut used to separate thebags during the production sequence.

The invention describes the vertical body seam becoming in effect, atear strip to assist in opening the bag. The invention relies on thethickness of the double layered body seam being more tear resistant thanthe adjacent bag material, thereby allowing the bag material to tearwhile the body seam remains intact.

In addition to the notch or serrations, an additional tear assistancefeature in the form of weakened or ‘scored’ lines or the like may beincluded without deviating from the scope of the invention. Scored linesare typically created in the outer or ‘face’ layer of the film and notthe inner protective barrier layer in order to maintain the integrity ofthe bag and therein protect the contents.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 Describes a perspective view of a vertical form-fill-sealmachine.

FIG. 2 Describes a perspective view of a filled and sealed bag.

FIG. 3 Describes a plan view of the back side of the present invention.

FIG. 4 Describes a plan view of the front side of the present invention.

FIG. 5 Describes a plan view of the front side of the present inventionwith opening structure partially torn.

FIG. 6 Describes a perspective view of the present invention with thetear strip removed and the bag opened to show access to the contents.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

As included in FIG. 1, bag construction material (10) comprises one ormore layers of flexible material and in a preferred embodiment,comprises a tear promoting film such as an oriented polymer material.These oriented materials are specially treated to create long, polymericmolecules which tend to align in a given manner, therein causing thematerial to tear in a predetermined direction. In a preferredembodiment, the bag material is oriented to allow the material topreferentially tear along the vertical axis of the bag, or moredescriptively, parallel to the orientation of the body seam.

In a preferred embodiment, preselected bag material (10) is cut to thedesired width and loaded into a bag making machine. FIG. 1 shows anexample of a vertical form-fill-seal machine that is commonly used topackage snack foods such as chips or the like. This illustration issimplified and does not show the cabinet and support structures thattypically surround the machine, but demonstrates the actions of theseveral elements of the machine. Packaging material (10) is pulled froma roll (11) and passes through tensioners (14) which are included tomaintain tautness. The material (10) is wrapped around a hollow, coneshaped product delivery tube (20) which typically features a round oroval cross-section. As the packaging material is pulled downward bydrive belts (21), the ends of the film are sealed together along itslength by vertical sealer (22) forming body seam (30). The machine thenapplies a pair of sealing jaws (40) against the tube form of the bag tocreate transverse seal (50). The product to be packaged is then droppedinto the bag through the opening at the top of product delivery tube(20) and is held within the bag above transverse seal (50). The bag thenproceeds off of product delivery tube (20) to sealing jaws (40) whereinthe top of the bag is sealed through transverse seal (50).

It is important to note and as described in the non-limiting embodimentshown in FIG. 1, sealing jaws (40) are swiveled approximately 90° toposition body seam (30) toward the end of sealing jaws (40). This actionis incorporated to reposition body seam (30) from the middle of the backpanel to a position in close proximity to the ends of top transverseflange seal (50A) and bottom transverse seal (50B). Other constructiontechniques which would relocate the body seam could be incorporatedwithout deviating from the scope of the invention.

In a preferred embodiment, transverse seal (50) comprises top transverseflange seal (50A) on bag (60) located below the sealing jaws (40) andbottom transverse flange seal (50B) on bag (70) being formed and filledabove sealing jaws (40). After transverse seal (50) has been formed, acut is made across the sealed area dividing transverse seal (50) intotop transverse flange seal (50A) and bottom transverse flange seal (50B)therein separating finished bag (60) below transverse seal (50) frompartially completed bag (70) above transverse seal (50). Additional bagmaterial (10) is then pulled into the machine to create the next bag inthe production sequence.

FIG. 2 describes an assembled, filled and sealed bag of the presentinvention including tubular body section (12), top transverse flangeseal (50A) including notch (75), bottom transverse flange seal (50B) andbody seam (30) positioned between the end of the top transverse flangeseal (50A) and the end of the bottom transverse flange seal (50B). In apreferred embodiment, the outside edge of body seam (30) will bepositioned at or near edge (6) of the bag. Also included and referencedby dotted line is score line (33) featured in the outer layer of the bagconstruction material and positioned in close proximity to body seam(30).

In an effort to describe the action of the opening structure, FIGS. 3, 4and 5 present the bag in a flat, plan view configuration, with the backside or back panel of the bag shown in FIG. 3 and correspondingly, thefront side or front panel shown in FIGS. 4 and 5. As shown in the art, aline running from the end of top transverse flange seal (50A) to thecorresponding end of bottom transverse flange seal (50B) will beconsidered edge (6) of the bag and which will, in a preferredembodiment, represent the outside edge of body seam (30).

As shown in FIG. 3, the back panel of the present invention includes toptransverse flange seal (50A) and bottom transverse flange seal (50B) andvertical body seam (30) which constructs the initial tubular body formof the present invention. Being tube shaped, the back panel iscontiguous with the front panel and is defined as being the materialbetween the edge of top transverse flange seal (50A) and the edge ofbottom transverse flange seal (50B) and sharing edge (6) with the frontpanel. Body seam (30) constructs the tube shape of the present inventionand runs vertically between the end of top transverse flange seal (50A)and the end of bottom transverse flange seal (50B) and is positionednext to edge (6). In this embodiment, body seam (30) is constructed asan overlapping seam, with inner edge (31) of body seam (30) not visibleif viewed from outside the bag but is referred to in the drawing as adashed line for clarity. The outer edge of body seam (30) could belocated along edge (6) of the bag, or body seam (30) could beincorporated as defining edge (6) without deviating from the scope ofthe invention.

As shown in FIG. 4, the front panel is defined as the body sectionterminating at the edges of top transverse flange seal (50A) and bottomtransverse flange seal (50B) and having edge (6) in common with the backpanel. In addition, score line (33) may be included in the front panel,and in a secondary embodiment, in the back panel, to assist in achievinga relatively straight tear when vertical body seam (30) is removed.

As shown in FIGS. 2, 3, and 4, top transverse flange seal (50A) includesnotch (75) which is included as a tear initiator. Notch (75) maycomprise a variety of shapes including triangular, circular or any othershape including a slit or serrated edge. In the embodiment shown, thetear initiator comprises a V shaped notch (75). Notch (75) may bedesigned to extend to the edge of top transverse flange seal (50A) ormay be designed to retain a small piece of intact material above notch(75) and below the cut edge of top transverse flange seal (50A). Thistype of notch (75) is designed to prevent the free edges of notch (75)from snagging and thereby opening the package accidentally.Additionally, notch (75) is cut to a limited depth in order to retainthe barrier properties created by top transverse flange seal (50A). Asshown in FIG. 3, notch (75) will be located next to vertical body seam(30), in close proximity to inside edge (31) of vertical body seam (30),a distance from edge (6) at least the width of body seam (30). This sametear initiation could be accomplished to a lesser degree through use ofa serrated cut line created when separating the individual bags inproduction and which produces top transverse flange seal (50A) andbottom transverse flange seal (50B) on adjacent bags.

In a preferred embodiment, and as best shown in FIGS. 2, 4, and 5, thepackage further comprises at least one score line (33) positionedbetween notch (75) and the bottom transverse flange seal (50B) runningparallel to body seam (30). As herein described, score lines areintended as an aid in directing the tear to follow a specific path.Score line (33) can be made through various techniques including laserscoring, slitting, or other material weakening technique. Regardless ofthe type of score incorporated, the barrier properties of the containerare retained, a provision which is essential in keeping oxygen andmoisture from contacting and adversely affecting the product within thecontainer. In a preferred embodiment, only the outer layer of materialis scored with the inner layer remaining intact and the barrierproperties of the container retained.

When the outer layer of the material is scored, a line of weakness iscreated which allows the bag material near notch (75) to tear andpropagate along score line (33) from the edge of top transverse flangeseal (50A) to bottom transverse flange seal (50B). In a secondaryembodiment, additional score lines could be included to enhance tearpromotion.

To open the bag, and as best shown in FIG. 5, a consumer will grip theedge of top transverse flange seal (50A) on both sides of notch (75) andpull outward to initiate a tear, then continue to pull outward anddownward thereby removing the outer strip of the bag including verticalbody seam (30). Because body seam (30) is included in the portion of thebag that is torn away, the inherent strength of body seam (30) willreduce the likelihood that the opening action will tear body seam (30)or will propagate in an uncontrolled direction. This action will befurther enhanced with the inclusion of score lines (33) on the frontpanel and/or back panel of the package.

As shown in FIG. 6, when the tearing action is completed and the tearstrip portion of the bag is removed, a consumer will be able to accessthe contents easily through product access opening (90). Because productaccess opening (90) is created along the longer side of the bag, greaterproduct access is afforded than is provided when using the flange sealend of a conventional bag.

Although the present invention herein described defines a food productbag, any appropriate non-food product could be included in the packagewithout deviating from the scope of the invention.

I claim: 1-12. (canceled) 13) A bag made of tear compliant material andfeaturing a tear-open strip, said bag constructed using a vertical bagforming machine, said construction comprising the steps of: wrapping bagconstruction material around the funnel shaped product delivery tube ofsaid vertical bag forming machine, said material overlapped and sealed,forming the vertical main body seam and therein creating the tubularbody section of said bag, fabricating a first transverse seal acrosssaid tubular body section therein creating a bottom seal, with theterminal end of said first transverse seal being positioned in closeproximity to said vertical main body seam, insertion of product to becontained into said bag through said product delivery tube, moving saidtubular body section downward and off of said product delivery tube,fabricating a second transverse seal across said tubular body sectiontherein creating a top seal, with the terminal end of said secondtransverse seal being positioned in close proximity to said verticalmain body seam, incorporating a tear initiation feature in the form of acut or notch into at least one said transverse seal in close proximityto said vertical main body seam, severing and removing said filled andsealed bag from said vertical bag forming machine. 14) The bag of claim13 wherein said vertical body seam comprises an outward projectingflange seal. 15) The bag of claim 13 wherein said vertical body seamcomprises a butt seam having no overlap of material or projecting flangeseal.